ML13146 Low Power DC – 1.8 GHz Transmitter LOW POWER INTEGRATED TRANSMITTER FOR ISM BAND APPLICATIONS SEMICONDUCTOR TECHNICAL DATA Legacy Device: Motorola MC13146 The ML13146 is an integrated RF transmitter targeted at ISM band applications. It features a 50 Ω linear Mixer with linearity control, voltage controlled oscillator, divide by 64/65 dual modulus Prescaler and Low Power Amplifier (LPA). Together with the receiver chip (ML13145) and either baseband chip (MC33410 or MC33411A/B), a complete 900 MHz cordless phone system can be implemented. This device may be used in applications up to 1.8 GHz. • Low Distortion LPA: Pout_1dB Compression Point 10 dBm • High Mixer Linearity: IIP3 = 10 dBm • 50Ω Mixer Input Impedance • Differential Open Collector Mixer Output • Low Power 64/65 Dual Modulus Prescaler (ML12054 type) • 2.7 to 6.5 V Operation, Low Current Drain (25 mA @ 2.0 GHz) • Powerdown Mode: <60 µA • Usable up to 1.8 GHz • Operating Temperature Range TA = –20° to 70°C Page 1 of 15 www.lansdale.com Note: Lansdale lead free (Pb) product, as it becomes available, will be identified by a part number prefix change from ML to MLE. Issue 0 ML13146 LANSDALE Semiconductor, Inc. Low Power Amplifier Power Gain @ 950 mA (matching required) Page 2 of 15 16 www.lansdale.com Issue 0 ML13146 Page 3 of 15 LANSDALE Semiconductor, Inc. www.lansdale.com Issue 0 ML13146 Page 4 of 15 LANSDALE Semiconductor, Inc. www.lansdale.com Issue 0 ML13146 Page 5 of 15 LANSDALE Semiconductor, Inc. www.lansdale.com Issue 0 ML13146 LANSDALE Semiconductor, Inc. CIRCUIT DESCRIPTION General The ML13146 consists of a low power amplifier, a 50 Ω linear mixer with linearity control, divide by 64/65 dual modulus prescaler and LPA. This device is designated for use as the low power transmitter in analog and digital FM systems such as UHF and 800 MHz Special Mobile Radio (SMR), UHF Family Radio Services, PCS and 902 to 928MHz cordless telephones. It features a mixer linearity control to preset or auto program the mixer dynamic range, an enable function and a wideband mixer output so the IC may be used either as an up converter or for a direct conversion source. Additional details are covered in the Pin by Pin Description which shows the equivalent internal circuit and external circuit requirements. where Cv is the equivalent capacitance of the varactor at the control voltage. For higher frequency operation, a series tuned oscillator configuration is recommended. Table 1 contains the S–parameters for the VCO transistor in a common collector configuration. This information is useful for designing a VCO at other operating frequencies or for various other oscillator topologies. The output power (at Mix/Buf Out) can be varied by adjusting the value of R5 as illustrated in Figures 3 and 4. Figure 5 shows the typical operating window for the prescaler. Current Regulation/Enable The device features temperature compensating, voltage independent current regulators which are controlled by the enable function in which “high” powers up the IC. Mixer: General The mixer is a double–balanced four quadrant multiplier biased class AB allowing for programmable linearity control via an external current source. An input third order intercept point of 20 dBm has been achieved. The mixer has a 50 Ω single–ended RF input and open collector differential outputs. An onboard Local Oscillator transistor has the emitter, base and collector pinned out to implement a low phase noise VCO in various configurations. Additionally, a buffered prescaler output is provided for operation with a low frequency synthesizer. For direct conversion applications the input of the mixer may be terminated to ground through a 120 to 330 Ω resistor. Local Oscillator/Voltage Control Oscillator The on–chip transistor operates with coaxial transmission line or LC resonant elements to over 1.8 GHz. Biasing is done with a temperature/voltage compensated current source in the emitter. A RFC from VCC to the base is recommended.The transistor can be operated in the classic Colpitts, Clapp, or Hartley configuration. The application circuit (Figure 8) depicts a parallel resonant VCO which can cover the entire 902 to 928 MHz frequency band with phase noise of approximately –80 dBc/Hz at a 10 kHz offset (see Figure 2). For this configuration, the LO will be driven with approximately 100 mVrms, and the frequency of oscillation can be approximated by: Page 6 of 15 www.lansdale.com Issue 0 ML13146 LANSDALE Semiconductor, Inc. The linear gain of the Mixer/Buf when used as a buffer is approximately –5.0 to –8.0 dB. Mixer/Buffer Outputs The mixer outputs (Mixer/Buf Out + and Mixer/Buf Out –) are balanced, open collector. A shunt resistor of 200 Ω minimum to VCC is recommended for stability. The outputs can be used as a single–ended driver or connected in a balanced–to–unbalanced configuration. If the single–ended driver configuration is used, the unused output must be tied directly to VCC. For the balanced–to–unbalanced configuration, an additional 3.0 to 6.0 dB of power gain can be achieved. Conjugate matching is easily accomplished to the desired load by the addition of a shunt and series element (see Table 2, S22 parameters). Mixer/Buffer Input The Mixer/Buf In pin is a broadband, 50 Ω input used to drive the IF port of the mixer (see Table 2, S11parameters). The Mixer/Buf In pin can be used in one of three modes: 1. A IF signal can be applied to this pin and up–converted to the desired RF frequency. 2. A resistor can be connected to ground, controlling the RF output power. 3. A resistor can be connected to VCC, disabling the entire mixer. Page 7 of 15 Low Power Amplifier (LPA) The LPA is internally biased at low supply current (approximately 2.0 mA emitter current) for optimal low power operation, yielding a 10 dBm 1.0 dB output power compression point. Input and output matching may be achieved at various frequencies using few external components (see Table 3 S–parameters). Typical power gain is 16 dB with the input/output conjugately matched to the source/load impedance. A minimum 200 Ω shunt resistor from the output to VCC is recommended for stability. www.lansdale.com Issue 0 ML13146 Page 8 of 17 LANSDALE Semiconductor, Inc. www.lansdale.com Issue 0 ML13146 Page 9 of 15 LANSDALE Semiconductor, Inc. www.lansdale.com Issue 0 ML13146 LANSDALE Semiconductor, Inc. Legacy Applications Information Evaluation PCB The evaluation PCB is a versatile board which allows the ML13146 to be configured as a basic transmitter, or to characterize individual operating parameters. The general purpose schematic and associated parts list for the PCB is given in Figure 9. This parts list build–up is identi- Page 10 of 17 cal to the Test Circuit illustrated in Figure 1, although parameters can very significantly due to differences in PCB parasitics. Figures 10, 11, and 12 show the actual PCB component, ground and solder sides, respectively. Please refer to AN1687/D and AN1691/D for additional details and applications for the device. www.lansdale.com Issue 0 ML13146 LANSDALE Semiconductor, Inc. Legacy Applications Information Page 11 of 15 www.lansdale.com Issue 0 ML13146 LANSDALE Semiconductor, Inc. Legacy Applications Information Page 12 of 17 www.lansdale.com Issue 0 ML13146 Page 13 of 15 LANSDALE Semiconductor, Inc. www.lansdale.com Issue 0 ML13146 Page 14 of 15 LANSDALE Semiconductor, Inc. www.lansdale.com Issue 0 ML13146 LANSDALE Semiconductor, Inc. Lansdale Semiconductor reserves the right to make changes without further notice to any products herein to improve reliability, function or design. Lansdale does not assume any liability arising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others. “Typical” parameters which may be provided in Lansdale data sheets and/or specifications can vary in different applications, and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer application by the customer’s technical experts. Lansdale Semiconductor is a registered trademark of Lansdale Semiconductor, Inc. Page 15 of 15 www.lansdale.com Issue 0